HUNTSVILLE, Alabama -- The brother of Grissom High School track coach/teacher David Yates, who was seriously injured Thursday when his bike hit a van at Lily Flagg Road and Hickory Hill Lane, said his family is disputing a police report that indicates Yates was riding on the sidewalk at a high rate of speed.

Huntsville police said a new witness has stepped forward today and wants to speak with investigators. There were no witnesses to the accident last Thursday other than the driver of the van and David Yates, who hasn't been able to speak about the accident yet.

"We're hoping this new witness can hopefully shed some light on the accident," Dr. Harry Hobbs, spokesman for Huntsville police, said. "We're encouraging anybody who knows anything about the accident to come forward. It was a tragic accident and our thoughts and prayers are with Mr. Yates, who has served this community by teaching the youths since the mid-1980s."

ates, 54, a Grissom teacher since the mid-1980s, remained in Huntsville Hospital's Surgical Intensive Care Unit in critical condition Monday, according to a Huntsville Hospital spokesman. Glen Yates, his brother, said David's injuries include collapsed lungs, a broken jaw, ribs, collarbone, scapula, eye socket and stitches. David wasn't wearing a helmet. Glen said after showing progress and even talking Saturday, David's breathing worsened because of his collapsed lungs and was put back on a ventilator Sunday. David has been unable to speak about the incident so far.

Glen says his family has issues with the accident report issued by the Huntsville Police Department. It states Yates was traveling on the sidewalk along Lily Flagg Road at a high rate of speed before he hit the Toyota minivan.

Glen said he talked to the first person on the scene of the accident at 6 a.m., a local chiropractor named Dr. Rachel Smith, and said she doesn't believe David was riding on the sidewalk or at fault. She didn't see the accident but believes David wasn't on the sidewalk based on the position she found him and his bike in the middle of Lily Flagg Road.

Hobbs said on Monday the department stood by its accident report but acknowledged Tuesday it was "still a preliminary report." The department didn't respond to requests to speak with the driver of the van involved in the accident.

"To me, my main concern is that David is such a well respected teacher and coach," Glen said. "They're saying he was at fault and in the wrong, so it's a matter of clearing his name."

The police report to the media stated: "The coach was on the sidewalk alongside Lily Flagg (on the north side) traveling eastbound approaching Hickory Hill. A Toyota minivan traveling on Hickory Hill southbound, reported he stopped at the stop sign, observed no traffic on the roadway and proceeded across the intersection. As the van got to the north side of the intersection, it was struck in the right side by the bicycle. It appears the bicyclist was traveling too fast to stop on the sidewalk, proceeded into the road and hit the van in the side as it drove on the road."

Glen doesn't believe his brother was riding on the sidewalk, especially after Smith met him at the intersection Friday and showed him the position and the blood stain where David landed.

"I've heard from dozens of people during the last few days who have seen David take that route and they've never seen him on the sidewalk," Glen said.

Smith said she was driving to a gym Thursday when she saw David lying in the middle of Lily Flagg Road and tried to stabilize his neck. She also heard the statement the man in the van gave police.

"He said, 'I stopped at the stop sign, looked right and left, and I didn't see any cars coming. So, I proceeded through the intersection, about the middle of the road, and I heard a thump.' And his next words were, 'I never saw him,' " Smith said.

Smith returned to the scene of the accident Friday to take photos for the family and found Glen already there. "I believe he was on the road riding a bike and think he hit the van. He was not on the sidewalk, he was following the rules of the road," Smith said.

*Updated at 11:53 to indicate a new witness has come forward and comments from Huntsville police.